Hi there! I think you should go ahead and apply, remember you are more then just numbers! However, there are a few things I think you should take into consideration:
1) Are you willing to retake the OAT? Can you explain your scores to your interviewer?
2) For the schools you're applying to, what is the average OAT score?
3) Do you feel like you've had adequate exposure to the field of optometry in terms of shadowing / work.
4) How is your academic trend? Do you show an improvement over time or consistency in grades when it comes to your sciences?
Also, make sure you have a very strong personal statement and recommendation letters! I personally think they make a huge difference when it comes to the application process. There have been many cases where people get in with 280s so be confident in yourself! Did you have any areas that you at least got 300+?